1. Field of the Invention
This invention relates to voltage adapters and, more particularly to an alternating current to direct current (AC-DC) voltage adapter including modules for providing multiple and variable DC output voltages.
2. Description of the Related Art
Conventional AC-DC adapters, used to convert an AC voltage, using a transformer, to a predetermined DC voltage, are well known and are used extensively. AC-DC adapters are generally able to receive a single AC input voltage and transform the AC voltage into a single DC output voltage. Some adapters have the capability to receive one of a variety of AC input voltages and subsequently, convert it to a single DC output voltage. This type of adapter is particularly useful for international travelers, who may encounter different commercial power standards in various countries.
Although, conventional AC-DC adapters are useful in providing AC-DC voltage conversion, the adapters are typically useful only with one electrical appliance at a time. Since the transformer in a conventional adapter is generally configured to provide one DC output voltage per AC input voltage, the adapter cannot be used simultaneously with multiple appliances requiring different DC operating voltages. Thus, each appliance must have provided a separate adapter. In the situation where access to AC power is limited to one, or else a few sources, the simultaneous use of multiple appliances requiring AC-DC conversion is limited.
What is needed is an adapter, which can provide multiple, simultaneous DC output voltages from a single AC power source.